US mobile ad spending is also expected to rocket, from $US1.17 billion in 2011 to $US2.29 billion in 2012, overtaking Japan as the top market, while the global figure will jump by more than 60 per cent to $US6.44 billion.

Mobile internet is the fast-growing advertising sector globally, but it remains a small player overall.

“Mobile advertising accounted for less than 1 per cent of total ad spending worldwide last year – and it will be a long time before it challenges other mainstay global advertising channels like TV, print and internet ads,” eMarketer said.

With Australia’s total advertising spending expected to exceed around $US15 billion this year, mobile internet ads will still only have a market share of around 0.5 per cent.